Carton loading systems are well known and generally have a conveyor that drives a series of carton carriers along a track from a first station where a carton is erected and placed in a carton carrier, to a second station where product is loaded into the carton held in the carton carrier, the carton thereafter being sealed, to a third station where the carton containing the loaded carton is discharged from the carton carrier.
In prior art systems the conveyor which drove the carton carrier along a track would operate intermittently (i.e. in other words it would be indexed from one position to the next, remaining stationary for a period of time at discrete intervals). One problem with this system is that the speed at which it can operate is limited. Furthermore, the system is noisy and there is considerable wear on the specific components of the system.
Although it is easier to design components for a system wherein the operations at the various stations take place when the carton carriers are stationary, due to the aforementioned problems there has been a desire to make the operation of the components in the carton loading system continuous.
Carton transfer devices have already been developed which can operate continuously (i.e. a carton can be removed from a carton storage magazine to be erected and placed in a carton carrier while it moving along a track driven by a continuous conveyor). Such an apparatus is disclosed in U.S. Pat. No. 3,937,458 which issued Feb. 10, 1976 and assigned to H. J. Langen & Sons Limited.
Also, various devices have been developed to discharge a loaded carton from a carton carrier while the carton and carton carrier are moving. Such a device would typically discharge the carton laterally from the carton carrier.
Although devices have been developed to provide for continuous placement and erection of a carton in a carton carrier, and to discharge a loaded carton from a carton carrier in a continuous manner, there is a certain inherent conflict. This is because it is usually desirable in the loading operation of the carton, to have the carton stationary relative to the loading device. This has posed design problems given the desire to have a conveyor that operates continuously.
One solution has been to have the continuous conveyor engage the carton carriers by a clutch mechanism. When the carton carrier, carrying an erected carton arrives at the loading station, an abutment device contacts the carton carrier to temporarily prevent movement of the carton carrier along the track. The clutch mechanism between the carton carrier and the continuous conveyor slips as the abutment device overrides the continuous conveyor. However, this type of loading station has considerable disadvantages. There will be substantial wear on the clutch mechanism when a carton carrier is stopped because the clutch mechanism does not disengage from the carton carrier but rather just slips. Furthermore, both the motion of bringing the carton carrier to a stop at the loading station and also the motion of the carton carrier as it moves away from the loading station will be erratic and will depend upon the operation of the clutch mechanism.
In order to overcome the aforementioned disadvantages of stopping the carton carrier at the station, one solution which has been generally adopted is to provide a second continuous conveyor device which moves buckets holding the product to be loaded into the carton. The second product conveyor is typically set up to run parallel and adjacent to the carton carrier conveyor and will operate at the same speed. Thus, buckets carrying product can be aligned and moved in synchronization with the carton carriers. Thus, there will be no relative movement of the bucket carrying the product relative to the carton carried by the carton carrier, and product can be laterally discharged from the bucket into the carton without having to stop the continuous conveyor and/or the carton carrier.
The problem with this system is that it requires a separate second conveyor device that will extend longitudinally parallel to the carton conveyor for some distance. Not only does such a device result in added expense but it will occupy a considerable amount of floor space, which in many commercial situations is very undesirable.
A further problem associated with carton loading systems is to provide carton carriers which are adaptable to accommodate cartons not only of a different width but also cartons of different depth.
The present invention seeks to overcome the aforementioned disadvantages of the known carton loading systems.